1. Field of the Invention
The present invention relates to a cartridge, particularly for storing and dispensing substances in paste form or capable of flow. The cartridge has at least one tube, for example a circular-cylinder tube, in which a closure piston and a dispensing piston adjustable by means of a piston rod are disposed, in each instance, so as to form a seal and to be displaceable, spaced apart from one another, in such a manner that a chamber for accommodating substances is formed between the dispensing piston and the closure piston. In this connection, an outlet opening is provided in each tube.
2. The Prior Art
Particularly in the dental sector, it is usual to store and transport materials in cartridges, from which these can be dispensed by way of a piston. Thus a dual cartridge is known from DE 100 38 882 A1, for example, in which two components for producing an impression mass are directly accommodated in the cartridges.
A dual cartridge structured in the manner of a syringe, in which two substances to be mixed with one another are accommodated in the chambers of this cartridge, which are oriented parallel to one another, is described in EP 1 426 017 A2. The two chambers have an opening at one end, in each instance, which are sealed by means of a closure part for transport and storage. To activate this dual cartridge, the closure part must be pressed into the chambers, so that a dispensing channel provided in the closure part is released. This method of procedure must be explained to a user before the first activation. Furthermore, this known dual cartridge can be used for only a single dose (unidose) and must be disposed of afterwards.
Alternatively to this cartridge, it is also known to package such materials in tubular bags, which can be introduced into the cartridges, which can then be used multiple times. On the one hand, it must be possible to seal such systems as hermetically as possible, for transport and storage, because the components can react with one another or with the surroundings or both. On the other hand, these systems must be easy for a user to open. For this purpose, the tubular bags must be pierced or cut open, without the components contaminating the reusable cartridges in this connection. In some application cases, this requirement has proven to be difficult.
Furthermore, a dual chamber syringe is proposed in DE 101 40 704 A1, in which a center plug, by means of which the dual chamber syringe is divided into two chambers, in which two components can be stored separated from one another, is provided, in addition to a dispensing plug. To apply these components, pressure is exerted on one of the components, by way of the dispensing plug, in such a manner that the center plug is pushed into a position in which it releases the bypass channel formed in the dual chamber syringe. In this open position, the center plug is locked in place by means of a projection on the inside of the syringe. The two substances can mix with one another, particularly if these substances are well-miscible liquids, and be dispensed jointly from the dual chamber syringe. Such dual chamber syringes, however, are also suitable only for one-time use, if the substances accommodated in the two chambers react with one another after mixing, and harden, for example. Furthermore, mixing of the two substances accommodated in the dual chamber syringe is perceived to require improvement, in some cases, particularly if these substances are not liquids.
A cartridge of the type stated initially is known from WO2005/016170 A2. Because the closure pistons of this known cartridge are freely movable in the tubes, they can slide out of their closure position during transport or storage. As a result, the substances accommodated in the cartridge can exit or react with one another or both. Penetration of germs into this known cartridge also cannot be optimally prevented.